From: John Ogness john.ogness@linutronix.de
[ Upstream commit 88fd1cb80daa20af063bce81e1fad14e945a8dc4 ]
After @blk_fill_in_prog_lock is acquired there is an early out vnet situation that can occur. In that case, the rwlock needs to be released.
Also, since @blk_fill_in_prog_lock is only acquired when @tp_version is exactly TPACKET_V3, only release it on that exact condition as well.
And finally, add sparse annotation so that it is clearer that prb_fill_curr_block() and prb_clear_blk_fill_status() are acquiring and releasing @blk_fill_in_prog_lock, respectively. sparse is still unable to understand the balance, but the warnings are now on a higher level that make more sense.
Fixes: 632ca50f2cbd ("af_packet: TPACKET_V3: replace busy-wait loop") Signed-off-by: John Ogness john.ogness@linutronix.de Reported-by: kernel test robot lkp@intel.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/packet/af_packet.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
--- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -989,6 +989,7 @@ static int prb_queue_frozen(struct tpack }
static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb) + __releases(&pkc->blk_fill_in_prog_lock) { struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(rb); atomic_dec(&pkc->blk_fill_in_prog); @@ -1036,6 +1037,7 @@ static void prb_fill_curr_block(char *cu struct tpacket_kbdq_core *pkc, struct tpacket_block_desc *pbd, unsigned int len) + __acquires(&pkc->blk_fill_in_prog_lock) { struct tpacket3_hdr *ppd;
@@ -2311,8 +2313,11 @@ static int tpacket_rcv(struct sk_buff *s if (do_vnet && virtio_net_hdr_from_skb(skb, h.raw + macoff - sizeof(struct virtio_net_hdr), - vio_le(), true, 0)) + vio_le(), true, 0)) { + if (po->tp_version == TPACKET_V3) + prb_clear_blk_fill_status(&po->rx_ring); goto drop_n_account; + }
if (po->tp_version <= TPACKET_V2) { packet_increment_rx_head(po, &po->rx_ring); @@ -2418,7 +2423,7 @@ static int tpacket_rcv(struct sk_buff *s __clear_bit(slot_id, po->rx_ring.rx_owner_map); spin_unlock(&sk->sk_receive_queue.lock); sk->sk_data_ready(sk); - } else { + } else if (po->tp_version == TPACKET_V3) { prb_clear_blk_fill_status(&po->rx_ring); }